Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Standard

Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample. / Béthermin, M.; Greve, T. R.; De Breuck, C.; Vieira, J. D.; Aravena, M.; Chapman, S. C.; Chen, Chian Chou; Dong, C.; Hayward, C. C.; Hezaveh, Y.; Marrone, D. P.; Narayanan, D.; Phadke, K. A.; Reuter, C. A.; Spilker, J. S.; Stark, A. A.; Strandet, M. L.; Weiß, A.

I: Astronomy and Astrophysics, Bind 620, A115, 01.12.2018, s. 1-19.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Harvard

Béthermin, M, Greve, TR, De Breuck, C, Vieira, JD, Aravena, M, Chapman, SC, Chen, CC, Dong, C, Hayward, CC, Hezaveh, Y, Marrone, DP, Narayanan, D, Phadke, KA, Reuter, CA, Spilker, JS, Stark, AA, Strandet, ML & Weiß, A 2018, 'Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample', Astronomy and Astrophysics, bind 620, A115, s. 1-19. https://doi.org/10.1051/0004-6361/201833081

APA

Béthermin, M., Greve, T. R., De Breuck, C., Vieira, J. D., Aravena, M., Chapman, S. C., Chen, C. C., Dong, C., Hayward, C. C., Hezaveh, Y., Marrone, D. P., Narayanan, D., Phadke, K. A., Reuter, C. A., Spilker, J. S., Stark, A. A., Strandet, M. L., & Weiß, A. (2018). Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample. Astronomy and Astrophysics, 620, 1-19. [A115]. https://doi.org/10.1051/0004-6361/201833081

Vancouver

Béthermin M, Greve TR, De Breuck C, Vieira JD, Aravena M, Chapman SC o.a. Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample. Astronomy and Astrophysics. 2018 dec. 1;620:1-19. A115. https://doi.org/10.1051/0004-6361/201833081

Author

Béthermin, M. ; Greve, T. R. ; De Breuck, C. ; Vieira, J. D. ; Aravena, M. ; Chapman, S. C. ; Chen, Chian Chou ; Dong, C. ; Hayward, C. C. ; Hezaveh, Y. ; Marrone, D. P. ; Narayanan, D. ; Phadke, K. A. ; Reuter, C. A. ; Spilker, J. S. ; Stark, A. A. ; Strandet, M. L. ; Weiß, A. / Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample. I: Astronomy and Astrophysics. 2018 ; Bind 620. s. 1-19.

Bibtex

@article{477572e24d0a4cefb94c02ca0b0a1454,
title = "Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample",
abstract = " The origin of the high star formation rates (SFR) observed in high-redshift dusty star-forming galaxies is still unknown. Large fractions of dense molecular gas might provide part of the explanation, but there are few observational constraints on the amount of dense gas in high-redshift systems dominated by star formation. In this paper, we present the results of our Atacama large millimeter array (ALMA) program targeting dense-gas tracers (HCN(5-4), HCO + (5-4), and HNC(5-4)) in five strongly lensed galaxies from the South Pole Telescope (SPT) submillimeter galaxy sample. We detected two of these lines (S/N > 5) in SPT-125-47 at z = 2.51 and tentatively detected all three (S/N ∼ 3) in SPT0551-50 at z = 3.16. Since a significant fraction of our target lines is not detected, we developed a statistical method to derive unbiased mean properties of our sample taking into account both detections and non-detections. On average, the HCN(5-4) and HCO + (5-4) luminosities of our sources are a factor of ∼1.7 fainter than expected, based on the local L′ HCN(5-4) - L IR relation, but this offset corresponds to only ∼2σ if we consider sample variance. We find that both the HCO + /HCN and HNC/HCN flux ratios are compatible with unity. The first ratio is expected for photo-dominated regions (PDRs) while the second is consistent with PDRs or X-ray dominated regions (XDRs) and/or mid-infrared (IR) pumping of HNC. Our sources are at the high end of the local relation between the star formation efficiency, determined using the L IR /[CI] and L IR /CO ratios, and the dense-gas fraction, estimated using the HCN/[CI] and HCN/CO ratios. Finally, in SPT0125-47, which has the highest signal-to-noise ratio, we found that the velocity profiles of the lines tracing dense (HCN, HCO + ) and lower-density (CO, [CI]) molecular gas are similar. In addition to these lines, we obtained one robust and one tentative detection of 13 CO(4-3) and found an average I 12 CO(4-3) I 13 CO(4-3) flux ratio of 26.1 -3.5 +4.5 , indicating a young but not pristine interstellar medium. We argue that the combination of large and slightly enriched gas reservoirs and high dense-gas fractions could explain the prodigious star formation in these systems. ",
keywords = "Galaxies: High-redshift, Galaxies: ISM, Galaxies: Star formation, Galaxies: Starburst, Submillimeter: Galaxies",
author = "M. B{\'e}thermin and Greve, {T. R.} and {De Breuck}, C. and Vieira, {J. D.} and M. Aravena and Chapman, {S. C.} and Chen, {Chian Chou} and C. Dong and Hayward, {C. C.} and Y. Hezaveh and Marrone, {D. P.} and D. Narayanan and Phadke, {K. A.} and Reuter, {C. A.} and Spilker, {J. S.} and Stark, {A. A.} and Strandet, {M. L.} and A. Wei{\ss}",
year = "2018",
month = dec,
day = "1",
doi = "10.1051/0004-6361/201833081",
language = "English",
volume = "620",
pages = "1--19",
journal = "Astronomy & Astrophysics",
issn = "0004-6361",
publisher = "E D P Sciences",

}

RIS

TY - JOUR

T1 - Dense-gas tracers and carbon isotopes in five 2.5 < z < 4 lensed dusty star-forming galaxies from the SPT SMG sample

AU - Béthermin, M.

AU - Greve, T. R.

AU - De Breuck, C.

AU - Vieira, J. D.

AU - Aravena, M.

AU - Chapman, S. C.

AU - Chen, Chian Chou

AU - Dong, C.

AU - Hayward, C. C.

AU - Hezaveh, Y.

AU - Marrone, D. P.

AU - Narayanan, D.

AU - Phadke, K. A.

AU - Reuter, C. A.

AU - Spilker, J. S.

AU - Stark, A. A.

AU - Strandet, M. L.

AU - Weiß, A.

PY - 2018/12/1

Y1 - 2018/12/1

N2 - The origin of the high star formation rates (SFR) observed in high-redshift dusty star-forming galaxies is still unknown. Large fractions of dense molecular gas might provide part of the explanation, but there are few observational constraints on the amount of dense gas in high-redshift systems dominated by star formation. In this paper, we present the results of our Atacama large millimeter array (ALMA) program targeting dense-gas tracers (HCN(5-4), HCO + (5-4), and HNC(5-4)) in five strongly lensed galaxies from the South Pole Telescope (SPT) submillimeter galaxy sample. We detected two of these lines (S/N > 5) in SPT-125-47 at z = 2.51 and tentatively detected all three (S/N ∼ 3) in SPT0551-50 at z = 3.16. Since a significant fraction of our target lines is not detected, we developed a statistical method to derive unbiased mean properties of our sample taking into account both detections and non-detections. On average, the HCN(5-4) and HCO + (5-4) luminosities of our sources are a factor of ∼1.7 fainter than expected, based on the local L′ HCN(5-4) - L IR relation, but this offset corresponds to only ∼2σ if we consider sample variance. We find that both the HCO + /HCN and HNC/HCN flux ratios are compatible with unity. The first ratio is expected for photo-dominated regions (PDRs) while the second is consistent with PDRs or X-ray dominated regions (XDRs) and/or mid-infrared (IR) pumping of HNC. Our sources are at the high end of the local relation between the star formation efficiency, determined using the L IR /[CI] and L IR /CO ratios, and the dense-gas fraction, estimated using the HCN/[CI] and HCN/CO ratios. Finally, in SPT0125-47, which has the highest signal-to-noise ratio, we found that the velocity profiles of the lines tracing dense (HCN, HCO + ) and lower-density (CO, [CI]) molecular gas are similar. In addition to these lines, we obtained one robust and one tentative detection of 13 CO(4-3) and found an average I 12 CO(4-3) I 13 CO(4-3) flux ratio of 26.1 -3.5 +4.5 , indicating a young but not pristine interstellar medium. We argue that the combination of large and slightly enriched gas reservoirs and high dense-gas fractions could explain the prodigious star formation in these systems.

AB - The origin of the high star formation rates (SFR) observed in high-redshift dusty star-forming galaxies is still unknown. Large fractions of dense molecular gas might provide part of the explanation, but there are few observational constraints on the amount of dense gas in high-redshift systems dominated by star formation. In this paper, we present the results of our Atacama large millimeter array (ALMA) program targeting dense-gas tracers (HCN(5-4), HCO + (5-4), and HNC(5-4)) in five strongly lensed galaxies from the South Pole Telescope (SPT) submillimeter galaxy sample. We detected two of these lines (S/N > 5) in SPT-125-47 at z = 2.51 and tentatively detected all three (S/N ∼ 3) in SPT0551-50 at z = 3.16. Since a significant fraction of our target lines is not detected, we developed a statistical method to derive unbiased mean properties of our sample taking into account both detections and non-detections. On average, the HCN(5-4) and HCO + (5-4) luminosities of our sources are a factor of ∼1.7 fainter than expected, based on the local L′ HCN(5-4) - L IR relation, but this offset corresponds to only ∼2σ if we consider sample variance. We find that both the HCO + /HCN and HNC/HCN flux ratios are compatible with unity. The first ratio is expected for photo-dominated regions (PDRs) while the second is consistent with PDRs or X-ray dominated regions (XDRs) and/or mid-infrared (IR) pumping of HNC. Our sources are at the high end of the local relation between the star formation efficiency, determined using the L IR /[CI] and L IR /CO ratios, and the dense-gas fraction, estimated using the HCN/[CI] and HCN/CO ratios. Finally, in SPT0125-47, which has the highest signal-to-noise ratio, we found that the velocity profiles of the lines tracing dense (HCN, HCO + ) and lower-density (CO, [CI]) molecular gas are similar. In addition to these lines, we obtained one robust and one tentative detection of 13 CO(4-3) and found an average I 12 CO(4-3) I 13 CO(4-3) flux ratio of 26.1 -3.5 +4.5 , indicating a young but not pristine interstellar medium. We argue that the combination of large and slightly enriched gas reservoirs and high dense-gas fractions could explain the prodigious star formation in these systems.

KW - Galaxies: High-redshift

KW - Galaxies: ISM

KW - Galaxies: Star formation

KW - Galaxies: Starburst

KW - Submillimeter: Galaxies

U2 - 10.1051/0004-6361/201833081

DO - 10.1051/0004-6361/201833081

M3 - Journal article

AN - SCOPUS:85058716088

VL - 620

SP - 1

EP - 19

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A115

ER -

ID: 222249501